I've got 50k on the clock on my fxdwg, it has this issue every once in a while where I'll be riding, the engine will cut out like it just lost gas, then it will come right back on and either run really well, or have very little power, until the next time that the engine stumbles, then it'll either run well or not. Vibrations will change too, when its low on power it'll shake more at idle and at freeway speeds, and rpms will be noticeably higher on the freeway. This happens randomly, maybe once a month or two, and its happened since I got the bike early this year. Does this sound like a lifter that collapses every now and then? I'm also hearing some whine and chirping from the engine, especially when its on its sidestand, so its probably time to replace the INA inner camshaft bearing as well. Should it put an aftermarket cam in while I'm in there? I'd like to primarily use the bike for highway touring so I want good gas mileage and reliability.

 

A collapsed lifter will let you know. When I got my bike put back together, one of the lifters had bled down and made quite a racket, probably because I was playing with the motor and turned it over with the kick lever quite a few times while it was out of the bike.:


Took a run around the block to pump it back up. Now it's nice and quiet again.

If you're running the stock inner cam bearing, you really should replace it ASAP, just to make sure.

From there, all the "may as well's" and "as long as I'm in there's" kick in: New cam, new lifters, port the heads, deck the cylinders, bump compression, etc, etc, etc

I think the best advice is to call Scott at Hillside Cycle and talk it over. He's a forum member, very generous with his time, and has forgotten more about these things than the rest of us will ever know. He will get you pointed in the right direction.

 

This is what my engine sounds like, not nearly as loud as your lifters, but there is some valvetrain noise in there. I'm probably going to use some adjustable pushrods to get the valves opening and closing just right. I should probably replace the fuel pump too, since its chirping like that.

 

You don't have a fuel pump, the carb is gravity fed. Do you have a FSM? Take 0maha's advice. Do the adj push rods if you must, but as part of a package.

 

I dont? 😓 that squeaking noise is coming from inside the gas tank. The ticking noise seems to be coming from the front cylinder, I just had the exhaust valve replaced in the front cylinder and we reused the stock solid pushrod. I have an fsm. I wish it was more detailed like a haynes manual.

 

I dunno what your squeaky thing is, but I bet it's related to that flapper intake. Dump that thing. Then check for a broken motor mount. Could be something rubbing under the tank too.

When it cuts out, is it like you hit the kill switch, that is, instant nothing, or is it like when you run out of gas, stumbles a bit, picks up, stumbles a bit, stops?

 

What you describe does not sound like a lifter issue. Sounds like electronic ignition issue. Intermittent loss of power, etc... start looking at all grounding, then ignition parts such as coil, pickup, etc...

 

When I hit the kill switch the engine still rolls for a sec, when the engine stumbles its like instant nothing under me. Like the engine has completely stopped, sudden loss of power, but then it fires right back up like nothing happened. The rear tire doesnt lock up so I'd assume the crank still spins when it happens.

 

Is there a good way tp check for a broken motor mount? Visual inspection everything looks good. All the bolts are tight and I cant move the mount by hand at all

 

1, at 50 K Your lifters are scary anyway toss em
2, -Your noise? a Lifter will sound like nasty thing going on in there...I cant hear it .
3. - like said that air box is doing you no favors, IDK why people buy that crap.